They should remove all the crap that is non-essential. For example, social and other things. Firefox size has nearly doubled in size between version 15 and 31. Also, I don't think that security would be good. I run noscript and similar. Notice how around slide 33 they said 3rd party cookies would be cleared? 3rd parties should not be allowed. Also, what if my trusted sites does not match their trusted list? Also, what if I don't want certain plugins to be enabled. Sounds less secure to me.